Edwin john fletcher



(No Model.)

B. J. FLETCHER.

MEANS FOR JOINING WOOD.

Patented Feb 24, 1891.

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UNITED STATES PATENT OFFICE.

EDWIN JOHN FLETCHER, OF NEW YORK, N. Y.

MEANS FOR JOINING W OOD.

SPECIFICATION forming part of Letters Patent No. 446,914, dated February 24, 1891.

Application filed December 5, 1889. Serial No. 332,682. (No model.)

.['0 all whom it may concern.-

Be it known that I, EDWIN JOHN FLETCHER, a citizen of the United States, residing in the city and county of'New York, in the State of New York, have invented a certain new and useful Improvement in Means for Joining Wood, of which the following is a specification.

I have in a United States Patent dated January 21, 1890, No. 419,763, shown provisions for imparting great strength to the corners of picture-frames and other structures by providing thin keys of open-work metal formed at right angles and inserting such with glue in saw-kerfs or analogous thin cavities made in the parts of the wood respectively. The present invention is in the same line. It is difficult to insure that the glue shall strike perfectly through the holes under suchconditions. I propose to overcomethe difficulty by previously gluing upon a metal core a thin surface of wood or analogous material, to which the glue subsequently applied can take a strong hold. The glue flows through the openings in the core and reliably holds the shaving or veneer of wood upon each face. At a later period the glue applied to the surface thus prepared secures the compound key reliably to the wood pieces in which they are fitted. The same kind of glue or other cement may be used for fastening the thin veneers of wood or other surfacing material upon the core as is subsequently applied to induce a strong union between the exterior of the veneer and the wood to be joined, or a different cementing material may be used in the two cases, as shall be found expedient; but in all cases the joining pieces are made complete at a previous stage, and are stored in a dried and complete condition ready to be used'when required. They may be straight for joining straight or angular for joining at an angle.

In the most complete form of the invention I join the wood by two such previously-formed joining-pieces, one a thin fastening, which I term a key, and another a thick fastening or dowel. The dowel may be round and inserted in holes bored with a bit or analogous tool. The key is flat and inserted in the thin cavities made by a saw or analogous device in each of the pieces to be joined. In joining the corners of a frame or box the flat key is L-shaped or formed at a right angle, and is fitted into a longitudinal saw-kerf previously formed in each piece, and the dowel is also L-shaped and extends longitudinally into a hole previously bored in each piece. The holes for the dowels and the saw-kerfs or other narrow cuts for the keys should be so arranged as to leave the front of the pictureframe or the top of the box or tray intact. The holes for the dowel may be bored from the joint. The saw-kerf for the fiat key may be made by a small circular-saw cutting .into the wood from the joint.

The accompanying drawings forma part of this specification and represent what I consider the best means of carrying out the invention.

Figure 1 is a face view of one corner of a picture-frame or analogous structure having the miter-joint at the corner re-enforeed according to my invention, the novel parts being indicated in dotted lines. Fig. 2 is a cross-section. Fig. 3 is a longitudinal section on the line 3 y in Fig. 1. Fig. 4 is a perspective View of the thin key. side View, and Fig. 6 is a cross-section, of the twisted or otherwise roughened angular wire, which forms the core of the round fastening or dowel. Fig. 7 is a side View, and Fig. 8 is a cross-section, showing the core with its round covering of wood or analogous material. Fig. 9 is a side view showing the construction of the dowel for a corner partially made. Fig. 10 is a similar View showing such dowel completed. The remaining figures show modifications. Fig. 11 is a side view and Fig. 12 a cross-section of a corresponding thin key in the form of a narrow strip. Fig. 13 is aside view, and Fig. 14 a cross-section, of a round fastening or dowel. Fig. 15 is a side View, and Fig. 16 a cross-section, showing another construction of dowel. Fig. 17 is a side view, and Fig. 18 is a cross-section, showing another construction of dowel. Fig. 19 is a side view, and Fig. 20 a cross-section, showing another construction of dowel. Fig. 21 is a side elevation showing another construction of the thin key. Fig. 22 is a cross-section of the same. Fig. 23 is a side elevation showing another construction of the thin key. Fig. 24 is a cross-section of the same. Fig. 25 is a side elevation showing another construction of the thin key. Fig. 26 is a cross-section of Fig. 0 Is a.

the same. Fig. 27 is a perspective view of a box or deep case having the four upright members or sides mitered at each corner and joined by an angular fiat key extending the whole depth. This form of fastening is very strong and contains a portion of my invention,but is open to the objection that the fastening-key is visible at the top and bottom or front and back. 28 and 29 are sections. Fig. 28 is a section on the line m :c in Fig. 21), and Fig. 29 is a section on the line y y in Fig. 28. Fig. 30 is a perspective view of a corner, showing in dotted lines the concealed fiat key without the dowel. This fig ure corresponds in construction to Figs. 4, 28, and 29. Fig. 81 is a cross-section on a larger scale. It shows a modified form of the dowel.

Similar letters of reference indicate corresponding parts in all the figures where they appear.

Referring to Figs. 1 to 12,inclusive, A and A are the pieces of wood to be joined. Holes a a are bored or otherwise produced in the positions shown to receive the dowel. Sawkerfs a a are also produced by the action of a saw. The thin keys are made each with a core of thin metal M, having perforations m and a facing of wood veneer or analogous material N on each face, all secured together by cement P. If the cement in the key adheres by its nature to the metal which constitutes its core, it increases the strength; but whether there is such adhesion or not the cement takes a strong hold on the metal by extending through the holes in. A good glue serves well as the cementing material.

The wood pieces A A previously well seasoned and accurately shaped to apply together and make a good joint at the corners, are sawed into from the miter-joint by a small circular saw or analogous device, which produces a narrow deepincision at the mid-depth, but will not extend either to the front or back face of the picture-frame or other structure being made. The core of the key is made from a circular blank, and is open-work to allow the glue to strike through, and is faced on one side or both sides with a thin veneer of wood or analogous material. \Vhen all is ready, the previously-made key and the pieces to be joined, being sufficiently coated with strong glue, are forced together. The key is received in. the thin sockets and take a hold. It is entirely concealed.

G II I is a dowel, G being a metal core of sufficientthickness to impart the required strength and roughened. II II are surfacing or coating pieces of wood, or they may be fabric, &c., steamed or otherwise softened and compressed upon the exterior of the core G. Cement I, which may be strong glue, is liberally supplied to join the several parts constituting a coating II together and to the roughened core. The roughening presents project ing points on the exterior of the core G,which engage with the glue and hold it firmly. If

the cement adheres byits nature to the core, it contributes greatly to the strength; but whether there is much adhesion or not, the cement engages with the core by hardening in such form as to strongly engage with its projections. oughly dried previously to their use. The angular dowels to join rightangled corners, as the corners of picture-frames, boxes, showcases, trays for showcases, book-cases, cameras for photographic purposes, and other boxlike constructions, maybe made by first producing straight dowels of wood and sawing them across at an angle of fort yfive degrees with the axis, and then properly turning and applying the miter-joints together. Each being bored out in the line of the axis and liberally supplied with glue may be forced home to an angle on a previously-formed core of iron. (See Figs. 9 and 10.)

I use the terms glue and cement as applied to either glue, ordinarily so called, or any material adapted to be softened by heat or by another agency and to be applied in a softened condition to stick parts strongly together on its hardening.

In applying the parts together the two pieces to be joined are heated, and the ends, including the interiors of the cavities a a, are bathed with thin glue, several times in succession, allowing it to become nearly dry between each treatment. After thus filling the pores and re-enforcing the strength of the wood, the holes a and the saw-kerfs a are again mechanically opened, if they have become partially filled with cement, and a fresh coating of strong glue or other suitable cement being applied in the cavities and along the joint of the wood, and also over the whole ex teriors of the dowel and key, the parts are applied together in the obvious manner, the angular dowel lying in the holes a of the pieces of wood, respectively. Then the thin key is forced into the saw-kerf or analogous narrow cavity a, and the wood is forced together. Any cement which may have have exuded should be removed. The whole is firmly held in position until the cement has set and the joint is complete. There may be any required finishing treatment.

It will be understood that the length of the doweland the size and form of the key should be properly determined prior to the insertion of each in their proper cavities.

Modifications may be made without departing from the principle or sacrificing the ad vantages of the invention. I can use two or more keys in applying together large moldings, as in the manufacture of heavy frames for pictures, looking-glasses, the.

Parts of the invention can be used without the Whole. In joining thin pieces, as the ebony, rosewood, or other wood used in the upright sides of trays for show-cases, I produce the proper saw-kerfs and use the angular key, but omit the holes and the dowel.

In joining straight pieces of wood or other The dowels are made and thoranalogous material the key and dowel, instead of being angular, should be straight. I can arrange the kerfs and keyin various angular and curved positions.

In the modifications shown in Figs. 13 and 14:, the core is a stout wire not roughened. A head is formed on each end of the core, which takes a firm hold on the covering material and gives great strength.

In the form shown in Figs. 15 and 16 the core is fiat and the covering'is in two halfround pieces secured to the flat core by transverse rivets.

In the form shown in Figs. 17 and 18 the roughened core is approximately round, but the covering is made in two parts. If the core is made sufficiently rough and the covering pieces sufficiently soft, either by using a wood which is naturally soft or by using wood or suitable analogous material, as papier-mache, steamed or otherwise prepared, so as to be soft at the time when itis applied, the two pieces of covering may be joined to the core by strong pressure. The roughnesses in the core imprint themselves into the covering material and hold it.

A peculiar construction is shown in Figs. 19 and 20. The metallic part or core is wirecloth or other thin material capable of being bent. The covering material of steamed wood or the like is applied on one side witha liberal quantity of cement, and the two materials are formed into a roll and confined until cold and dry. Care should be taken with this form to arrange the wood covering to apply outside of the metal. The thin metal may be perforated, allowing the glue to strike through the perforations.

The remaining modifications relate to the flat key. Figs. 21 and 22 show wire-cloth core in an extended condition with a wood covering applied upon each side, with cementing material engaging the covering on the two sides together and to the metal by striking through the holes in the latter.

In the form shown in Figs. and 24L the metal core is not perforated,but is deeply cut into through each side. The cement engages through the deep notches thus formed.

In the form shown in Figs. 25 and 26 the core is formed of a number of roughened, waved, or corrugated wires. The waves in the wire should be all in or near a single plane. The glue strikes through the space between these wires and engages the wires by means of the waves or roughnesses.

Fig. 27 shows the thin keys applied to hold the wood parts together extended completely through from the back to the front.

Fig. 28 is a horizontal section, and Fig. 29 is a vertical section, of the preferable form shown in perspective in Fig. 30.

Fig. 31 is a cross-section on a large scale, showing a modification in the construction of the wood fastening-the dowel. In this mode of constructing the dowel the metal core,

either smooth or roughened,is thickly coated with an adhesive cement, (thin putty of oil and whiting will serve,) and is then covered with short vegetable fibers, or other fibers of proper toughness adapted to receive and adhere to glue. The fibers stick strongly to the metal by the action of one kind of cement, and stick strongly to the wood of the pictureframe or other article by virtue of another kind of cement.

In all the formsI can use for the core of the thin key either perforated or otherwise prepared open-work sheet metal or wire-cloth or various other forms of fiat open-work core. I can use other strong material than metal. Horn or hard rubber will serve; butI prefer steel or iron.

It is the function of the core to give strength. My invention allows it to be of material which by reason of its lack of chemical aflinity or other cause is not well adapted to be cemented in the ordinary manner. The core may be any strong and durable material of the proper form which is not adapted to be glued or is less adapted to be glued than wood.

The surfacing material may be thin shavings of wood, or they may be other material than wood. Paper or leather may serve.

I propose in some cases to apply the glue or other good cement to the thin perforated or open-work core so that it will flow through the opening therein, and when it is sufficiently dry and tacky apply sawdust or analogous material in the form of small regular or irregular fragments and cause them to adhere. Pressure may be appliedif necessary. Such key when dried will serve to a degree the same purposes as the more elaborately faced.

In making the round fastenings, which I have termed dowels, the core may be wire rope or barbed wire. I propose for ordinary cases to use square or flat wire twisted. Some degree of success may be attained with smooth wires. The adhesion of proper cement thereto is considerable. It is preferable, however, that they be roughened, so that the cement may engage strongly in either the round or the flat form of my fastenings. The roughnesses ,may be made by inducing portions to project beyond the general surface or by indenting or making recesses within the general surface. I can bite with acid or etch recesses in the metal cores. A good portion of the result may be attained by facing only one side of the flat key with very thin veneer. I can make an excellent rough core for the round fastening by screw-threading a wire of proper size. The threads obviously need not be perfect. They may be produced by passing the wire through a pair of steel rollers properly toothed to produce an approximate screw-thread.

\Vith any of the forms of core or of the entire joining-piece it is practicable to press the covering directly upon the core and secure a strong union of the covering and the core,

which union cannot be secured with nearly the same perfection when the core is simply forced endwise into a recess, as in my former patent.

I claim as my invention- 1. The flat compound joining-pieces described, having a surface of wood or analogous material adapted to be glued joined to a core of iron or analogous material less adapted to be glued, but giving the required strength, substantially as herein specified.

2. An angular key or joining-piece having a surface of wood or analogous material adapted to be glued and an open-work core of iron or other strong material, the surface and the core being previously joined by cementtaking hold through the opening, adapted to serve in securing together pieces A A in angular positions, substantially as herein specified.

3. A wood-jointeomposcd of two pieces A A united at an angle by glue or analogous cement, in combination with each other and with a previously-made angular joiningnece of compound structurehaving a core of metal and a surface of material adapted to be glued or cemented thereon, all substantially as herein specified.

4. The fiat thin opeirwork key having a core of metal faced with wood or analogous material adapted to be glued, the surface material being previously joined to the core by cement taking hold through the opening, as herein specified.

5. The concealed joint described, having two pieces of wood applied together, with the matching face of each scored by a circular saw or analogous tool to make a thin incision extending along only a portion of the joint, in combination with each other and with a corresponding thin key of slightly less extent, and havinga surface adapted to be glued inserted in such scores and secured by gluing or cementing, as herein specified.

(J. The two different joining-pieces,the first flat and matching in thin recesses, as sawkcrfs, the other approximately round and matching in approximately round holes, each joinedangularly and having a metal core and a previously-cemented surface of Wood or analogous material adapted to be glued, in combination with each other and with the pieces A A joined thereby, all arranged to serve substantially as herein specified.

In testimony whereof I have hereunto set my hand, at New York city, this 7th day of November, 1889, in presence of two subscribing witnesses.

ED'\\"I\ JOIIN liLE'lCllER.

, \Vitnesses:

(/I'IARLES F. llxn'rnn, NonRIs A. CLARK. 

